The use of soft pads for buffing, polishing or otherwise finishing the painted surfaces of automobiles is well known. Depending on the finish desired, the buffing or polishing may require several steps, and the use of multiple finishing compounds. In order to perform these steps, the soft buffing pads are removably attached to a buffing machine, such as a motorized buffer or polisher. The buffing machines typically include a generally disk-shaped backing mount to which the buffing pad is attached. The backing mount is rotationally driven by the motor of the buffing machine, causing the attached buffing pad to rotate. As the buffing pad rotates, the finishing compounds help smooth out irregularities in the painted surfaces being finished, producing a sheer, glossy shine on the automobile.
A number of different types of buffing pads may be used to create the desired finish. For example, wool or other fabric pads are sometimes employed, generally in the early stages of the finishing process. During the later stages of finishing a painted surface, foam pads are typically used. The resiliency of foam provides a very soft surface so as to avoid excessive pressure on the finishing compound against the surface. However, due to the speed at which the buffing pad is being rotated during operation, conventional buffing pads produce a significant amount of heat due to friction between the pad and the surface to be finished. Prolonged use of conventional buffing pads, therefore, may result in the buildup of frictional heat sufficient to damage the surfaces being finished (e.g., burn the paint on the surface).
For example, many conventional buffing pads are fabricated having a convoluted or "egg crate" polishing surface in which projecting portions of the convoluted surface are separated from each other by recesses between the projections. Frictional heat generated at the convoluted surface of these buffing pads remains trapped within the recesses of the buffing pad. Moreover, the convoluted polishing surfaces of these buffing pads tend to wear down with moderate use, such that the danger of harmful thermal buildup at the polishing surface may increase over the life of the buffing pad. Additionally, the projecting portions of these convoluted pads tend to wear down more rapidly than the rest of the pad, and consequently, the convoluted pads become nearly flat after prolonged use.
Another problem often experienced during the use of conventional buffing pads is the tendency of such pads to bounce or skip across the surface to be finished when rotated at high speeds. This produces not only an uneven finish on the surface to be polished, but also significant operator discomfort as a result of trying to control the buffing pad.
Additionally, various attempts have been made at providing a means for properly aligning conventional buffing pads with the backing mount (See U.S. Pat. No. 5,123,139 to Leppert et al.). Centering the relative components of the buffing pad assembly is important as an off-centered buffing pad may create a balancing problem, causing the buffing pad to wobble. The resulting vibration produced by an off-centered buffing pad may result in an inferior buffing or finishing job. Moreover, attempts to overcome the vibration produced by an off-centered buffing pad can easily fatigue the operator of the buffing machine.
Leppert et al. discloses the use a frustro-conical centering post on the buffing pad. In order to help secure the centering post to the buffing pad, the centering post disclosed in Leppert et al. is located underneath a layer of fastening material. As a result, the attachment between the fastening material and buffing pad is relatively weak at the interface of the centering post and the fastening material. Moreover, it is often difficult to secure the fastening material to the centering post. Therefore, in the centering systems such as the one disclosed by Leppert et al., the fastening material is more prone to separate from the buffing pad after moderate use.
Consequently, a need exists for an improved buffing pad assembly for use in polishing, buffing or otherwise finishing painted surfaces.